Bayer and Johnson & Johnson have won the first of around 18,000 lawsuits lawsuit being brought by US patients who claim the blood-thinning drug Xarelto caused their uncontrollable brain and gastrointestinal bleeding.

A federal jury in New Orleans, Louisiana found that the two companies, which developed Xarelto together and market it separately in Europe and the US, did not defectively design the drug nor mislead a Louisiana man and his doctors about the health risks.

Attorneys for the patients contend that J&J and Bayer should have warned patients that they could be tested to assess their bleed-out risk before taking the blood thinner, prescribed to prevent blood clots that can lead to fatal heart attacks and strokes, The drugmakers, however, said the New Orleans jury’s verdict finding affirms their product’s safety.

“The FDA-approved label contains accurate, science-based information on the benefits and risks of this life-saving medicine,” a J&J spokesperson told the news agency Bloomberg, while a US spokesperson for Bayer, said the New Orleans decision “reflects the facts of this case and the appropriateness of the Xarelto prescribing information.”

Three additional bellwether cases are expected to be heard over the next three months. Next up is a suit brought by the husband of a woman who used Xarelto for about a month before she died from a cerebral hemorrhage.

Xarelto is Bayer’s top-selling drug, with sales of around €3 billion ($3.24 billion) in 2016. It is J&J’s third-largest in terms of revenue, accounting for $2.29 billion last year. The blood thinner belongs to a new class of drugs designed to replace top-seller Coumadin, developed by a unit of US drugmaker Bristol Myers and on the market since the 1960s.

The difference between Xarelto and Coumadin, critics say, is that Xarelto has no antidote, so that some users are at high risk for bleeding out if they suffer an injury. Coumadin’s blood-thinning effects can be reversed, however.